在IIS7群集上运行的PHP上调试500内部服务器错误

Recently my ISP switched our website to an IIS7.0 high availibility cluster. The website is running on PHP5.2.1 and I can only upload files (so no registry tweaks). I had tested the website before and everything seemed to be working, but now the checkout page fails with:Recently my ISP switched our website to an IIS7